An aircraft pallet is generally a tray arranged horizontally on a shelf, designed to support electronic apparatus or avionics units enclosed in a boxlike case. Accordingly, the pallet comprises slideways enabling the avionics unit to be inserted therein by sliding from front to back, the latter's bottom sliding on the pallet or tray itself during installation. The slideway may consist merely of the top surface of the pallet and two side shoulders guiding the unit. At the back of the pallet is a vertical wall carrying the electrical connector or connectors intended to mate with matching connectors on the rear panel of the pallet-mounted avionics unit.
Hinged locks are generally provided to lock the electronics unit in its final pushed-back or home position, such locks sometimes being operable to help slide the unit inwards or outwards on the pallet, in which case they are commonly equipped with releasing means which cut out the transmission of the pushing-in force normally transmitted by the hinged lock to the electronics unit when an installer meets a certain sufficient resistance which should correspond to full mating of the connector halves.
In most aircraft, a plurality of avionics units are arranged side by side, generally on a rack, with tight spacing between them. The operator or pilot therefore can see only the front panels of the units and can never be certain whether a unit is duely and fully pushed in for perfect mating of the aforementioned connectors and adequate electrical connection. The use of hinged locks is intended to obviate this disadvantage. However, the lock mechanism can still release prior to actual mating of the connectors, or without full engagement together of said connectors, conveying a false sense of security that will not preclude an avionics malfunction due to a poor connection. Obviously, the problem is aggravated when non-standard or different standard-sized electronics units are installed together.
Assignee has already proposed, in French published patent application FR-A-2546676, a connector mating indicator consisting of a detector, placed near the back panel of the aircraft pallet, which slides between a forward position and a backward position corresponding to the rearmost position of the electronics unit rear panel at which connector mating is fully effected, said detector being connected to the rear end of a long lateral tongue or strip guided along the pallet, the forward end whereof is colored and is visible at the front of the pallet when the detector is in forward position and disappears from sight when the detector is backed to the rear of the pallet or tray.
The present invention is directed to obviating the disadvantages of the prior art devices and to using mechanical indication means towards this purpose to the least possible extent.
Another object of the invention is to enable an operator to visually determine whether the hidden connectors are correctly mated with the help of an external light source such as a flashlight.
Still another object of the invention is to enable the operator to visually determine whether connector mating is adequate, without powering up the device.